1. Field of the Invention
The present invention relates to a fluid control valve, and more particularly, to a fluid control valve which can be suitably used in a hydrogen gas supply system for supplying hydrogen gas to a fuel cell in a fuel cell electric vehicle.
2. Description of the Related Art
Typical fuel injection valves for supplying fuel to an internal combustion engine are designed such that a fuel injection nozzle is closed or opened by movement of a movable valve disposed within a valve body. The movable valve moves by a biasing force generated by a spring and by an electromagnetic force generated by energization of a coil. The valve body comprises a body, a core, a valve seat, which are fitted together. Rubber O-rings are provided in each of the joints of the body, the core, the valve seat. A fluid control valve using a sealing structure having such rubber O-rings is disclosed in WO2003-42526 and Japanese laid-open patent publication No. 9-310656.
Recently, fuel cell electric vehicles with a fuel-cell-power generation system have been developed. The fuel cell power generation system includes a fuel cell that generates power by electrochemical reaction between hydrogen and oxygen, an oxygen supply device that supplies oxygen to the fuel cell, and a hydrogen supply device that supplies hydrogen to the fuel cell. The fuel cell electric vehicle is driven by a driving motor which is supplied with electric power generated by the fuel cell.
A typical hydrogen supply system used in a fuel cell electric vehicle includes a hydrogen storage container for storing hydrogen, a cut-off valve and a regulator which are disposed between the hydrogen storage container and the fuel cell. The regulator reduces the pressure of hydrogen gas supplied from the hydrogen storage container, to a set pressure. As the regulator, for example, a mechanical fluid control valve is used which reduces the pressure of inputted hydrogen gas to a set pressure which is defined by the biasing force of a spring. The cutoff valve is opened when the ignition switch is turned on, while it is closed when the ignition switch is turned off. Hydrogen gas in the hydrogen storage container is supplied to the fuel cell via the regulator when the cutoff valve is opened, while the supply of hydrogen gas to the fuel cell is stopped when the cutoff valve is closed.